Hula Hoop Help

Ok...a bit random...but I'm told Hula Hooping is a good way to tone the old love handles, so today on a whim I picked up DD's hula hoop and had a go. Pretty sure I could do it, after a fashion, when I was a kid but could not do it for the life of me today.

The only time I got any kind of momentum going it started to wobble crazily and then dropped like a stone. Landed on my bare foot and it hurt. Possibly it doesn't help that it's one of these Wave hoops with water inside. I thought that was supposed to help to balance it or something but in my case it just made it painful.

Any tips? Anyone tried these crazy Wave hoops? Do I need a lighter hoop? Bigger diameter? Smaller? Or to just accept that I'm too old for all this wiggling about and get back on the sofa?